<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        :root {
            --short: 8px;
            --long: 40px;
        }
        body {
            display: flex;
            height: 100vh;
            margin: 0;
            justify-content: center;
            align-items: center;
            background-color: #0c1c38;
        }
        #container {
            display: flex;
            width: 65px;
            height: var(--long);
            justify-content: space-evenly;
            align-items: center;
        }
        #container span {
            display: inline-block;
            position: relative;
            width: 9px;
            height: var(--short);
            background-color: lightblue;
            animation: beating 1.5s ease-in-out infinite;
        }
        #container span:nth-child(2) {
            animation-delay: .2s;
        }
        #container span:nth-child(3) {
            animation-delay: .4s;
        }
        #container span:nth-child(4) {
            animation-delay: .6s;
        }
        #container span:nth-child(5) {
            animation-delay: .8s;
        }
        @keyframes beating {
            0% {
                height: var(--short);
                background-color: lightblue;
            }
            25% {
                height: var(--long);
                background-color: #409eff;
            }
            50% {
                height: var(--short);
                background-color: lightblue;
            }
            100% {
                height: var(--short);
                background-color: lightblue;
            }
        }
    </style>
</head>
<body>
    <div id="container">
        <span></span>
        <span></span>
        <span></span>
        <span></span>
        <span></span>
    </div>
</body>
</html>